Volcanic Earthquakes and Tremor at Kilauea Volcano : Source Mechanisim in Relation to Volcano Structure Eruptive Processes

这次与美国火山学家的合作实验是在夏威夷基拉韦厄火山山顶附近进行的。在五天的时间里，安装了三个地震天线，在七个永久宽带站的基础上增加了三个临时宽带站，并安装了一条120个分量的地震反射线。在实验期间，基拉韦厄火山正在经历一个不寻常的地震活动期，这与持续10年的Puu Oo火山喷发有关。通过对这次试验资料的分析，阐明了地震事件的一些特征，总结如下：观测到伴随超长周期脉冲的地壳变形。脉冲的粒子运动图表明，这些信号的来源来自山顶陨石坑的北缘附近。由于地壳变形被认为是岩浆活动引起的，所以超长地震信号可能与岩浆活动有关。通过对宽带台站新获得的资料的详细分析，阐明了地壳形变和地震脉冲的源机制。在实验中，观测到许多火山地震。用MUSIC方法对火山信号进行频率慢度阵列分析，发现信号来自山顶火山口。用地震天线对数据进行精确分析，将显示地震事件的波形和峰顶区域以下地下结构的详细性质。

The cooperative experiment with U. S. volcanologists was conducted around the summit area of Kilauea volcano, Hawaii. Over a five day period three seismic antennas, three temporary broadband stations added to the seven permanent broadband stations, and a 120-component seismic reflection line were installed. During the experiment, Kilauea Volcano was undergoing an unusual period of seismic activity associated with a protracted transient in 10-year-long Puu Oo eruption. Analyzing the data of this experiment, some features of the seismic events are clarified as are summarized below.The crustal deformation accompanied with the very-long period pulses was observed. Particle motion plots for the pulses indicate that the source of these signals originated near the north rim of the summit crater. Since the crustal deformation is thought to be caused by the magma activities just blow the crater, the very-long-seismic signals may be related to the magma activities. The source mechanism of the crustal deformation and the seismic pulses will be clarified by the detailed analysis of the data newly obtained by the broadband stations.During the experiment, many volcanic earthquakes were observed. Frequency-slowness array analyses of volcanic signals by way of MUSIC method present that the signals came from the summit crater. Precise analyses of the data with the seismic antennas will show the detailed nature of the waveforms of the seismic events and the underground structure below the summit area.